Too many commands to execution: the maximum allowed count of commands is 64

It is a separate email sent to them by "mailserver" suggesting that they fix the script. Of course, they don't have the slightest idea what to do. Neither do I. Remember that I am the admin on the Kerio Connect system, so I won't be able to fix most things that are private to these accounts. I need a fix that a user can implement.

We need more information.
Who gets the mail, quote the mail here, post logs, what is "Mailserver", how's your infrastructure etc. pp.

Basically you just said "My car makes weird sounds" and that's it.

Give us something to work with.

And enable SMTP Debug msgs and post them if the error occurs again with the right lines. Might be from SMPT send/receive part, that another mailserver tries to deliver a mail, but is blocked because he used too many smtp commands. So something like a hacking / antispam protection is kicking in.

Too many commands to execution: the maximum allowed count of commands is 64

It is a separate email sent to them by "mailserver" suggesting that they fix the script. Of course, they don't have the slightest idea what to do. Neither do I. Remember that I am the admin on the Kerio Connect system, so I won't be able to fix most things that are private to these accounts. I need a fix that a user can implement.

What does this message mean and how do I (or my users) fix it?

Looks like mail filter script for that user mailbox may be corrupted. Look at user mail filter rules or according filter.siv file in user mailbox.

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